The complex genetics of NIDDM have so far hindered the identification of its etiology. We plan to identify over 300 affected sibling-pairs with NIDDM to obtain family, demographic, physical exam and historical information as well as a single blood sample of genomic DNA. By utilizing PCR technology, the entire genomic will subsequently be screened for loci associated with NIDDM in sibpairs. Although a small number of visits was recorded for this protocol, a larger number of samples was submitted to the Core Laboratory for subjects not seen on the GCRC.